For the resident experts: Probably Peter and Will: The switch on the lower left of the speedo pod (splitty) that controls the power to the rear dome light in a bus; the DC has a hole for one but is it supposed to have the switch to work the rear dome light in the DC as in the regular busses. The SC obviously does not have one (no rear dome light). Friend has a double cab but the hole for the switch has what appears to be a factory installed rubber plug in the hole and does not have a switch. I don't know if the DC is supposed to have one or not. Sammie